Apparatus and method for testing brake actuator units used in railroad cars

Abstract

An apparatus for testing tread and disk brake actuator units for use in railway cars in an overhaul backshop environment is disclosed. The apparatus includes a test bench on which multiple test fixtures are mounted to simultaneously receive and test a like number of brake actuator units. Each test fixture is provided with differently sized sets of brackets to enable respective simultaneous mounting of different brake actuator units made by a variety of manufacturers. The test bench includes a series of solenoids and directional valves operated by a programmable logic controller to supply low, high and maximum pressure air to the actuator units to perform pneumatic leakage, applied force, and slack adjuster travel tests. Pneumatic leakage detection is performed through an automatic test removing human subjectivity from the test process. A diagnostics panel provides functional information on the status of the equipment on the test bench. A control panel enables the test operator to select between automatic and manual modes of operation and to observe lights indicative of test type, cycle and pass versus failure mode following test completion.

What is claimed is: 
     
       1. Apparatus for testing brake actuator units for use in railway cars, comprising: a. a test stand;   b. a plurality of differently sized sets of brackets to which a brake actuator unit is mounted to one of said sets;   c. control means for applying pressurized air to the brake actuator unit and monitoring for pressure drop indicative of air leakage within a cylinder of said actuator unit; and   d. means, responsive to a signal from the control means, for identifying whether a predetermined amount of leakage is present.   
     
     
       2. Apparatus of claim 1, wherein said control means includes means for selectively applying a predetermined low pressure and a predetermined high pressure to said cylinder to establish a low leakage test and a high leakage test, respectively. 
     
     
       3. Apparatus of claim 2, wherein said selectively applying means applies a predetermined maximum pressure to establish a maximum pressure leakage test. 
     
     
       4. Apparatus of claim 2, wherein said selectively applying means includes an air circuit having a source of pressurized air connected to the cylinder through a pressure regulator and a directional valve, said pressure regulator regulating the pressure to a desired level and said directional valve being moveable between open, closed and exhaust positions. 
     
     
       5. Apparatus of claim 1, further comprising a plurality of test stands for respectively testing a plurality of brake actuator units, and said control means enabling pressurized air to be supplied to selected ones of said cylinders of the respective units being tested. 
     
     
       6. Apparatus of claim 1, wherein said control means includes a pressure transducer for monitoring the pressure supplied to the cylinder, said pressure transducer being connected to a display meter which actuates a programmable logic controller (PLC) which in turn actuates the identifying means when predetermined leakage is present. 
     
     
       7. Apparatus of claim 1, wherein said differently sized sets of brackets each include different pairs of upper and lower brackets positioned on the test stand for direct alignment and attachment with mounting locations formed on a housing of said brake actuator unit. 
     
     
       8. Apparatus of claim 1, further comprising a load cell mounted to the test stand in operative alignment with a cylinder actuated component of the brake actuator unit to measure application of force of said component under extension by said pressurized air. 
     
     
       9. Apparatus of claim 8, further comprises a gauge and an indicator connected to the test stand and the cylinder actuated component to measure slack travel of said component. 
     
     
       10. Apparatus of claim 1, wherein said control means is operable in automatic and manual modes of operation. 
     
     
       11. Apparatus of claim 2, said control means further comprising a programmable logic controller and a diagnostic panel display, connected to said programmable logic controller, said diagnostic display panel including indicia for indicating the type of pressure test being conducted and further indicia indicating whether or not leakage occurs following completion of said pressure test. 
     
     
       12. Apparatus of claim 11, further comprising a control panel display connected to the programmable logic controller and including indicia representative of whether a unit under test has passed or failed the leakage test at said high and low pressure levels. 
     
     
       13. Apparatus for testing brake actuator units for use in railway cars, comprising: a. a test stand;   b. a mounting bracket set located on said test stand to mount the brake actuator unit to the stand;   c. control means for applying pressurized air to the brake actuator unit and monitoring for pressure drop indicative of air leakage within a cylinder of said actuator unit; and   d. means, responsive to a signal from the control means, for identifying whether a predetermined amount of leakage is present.   
     
     
       14. Apparatus of claim 13, further comprising a plurality of differently sized sets of brackets to which a brake actuator unit is mounted to one of said sets, whereby said differently sized sets enable brake actuator units of different manufacturers with different mounting holes to be mounted to the same test stand. 
     
     
       15. Apparatus of claim 13, wherein said brake actuator unit is a disk brake actuator and said mounting bracket set is arranged to directly bolt to a housing of said brake actuator unit with a cylinder actuated component part of said unit being moveable in a vertical direction on said test stand. 
     
     
       16. Apparatus for testing brake actuator units for use in railway cars, comprising: a. a test stand;   b. mounting brackets attached to said test stand to mount said brake actuator unit on said stand;   c. control means for applying pressurized air to the brake actuator unit to extend a cylinder actuated component thereof;   d. a load cell mounted to the test stand to contact the component in an extended condition thereof said load cell being connected to means for displaying an application force of said component against said load cell.   
     
     
       17. Apparatus for testing brake actuator units for use in railway cars, comprising: a. a test stand;   b. mounting brackets attached to said test stand to mount said brake actuator unit on said stand;   c. a control system operatively arranged to apply pressurized air to the brake actuator unit to extend a cylinder actuated component thereof; and   d. a load cell mounted to the test stand to contact the component in an extended condition therewith, said load cell being connected to a display for displaying an application force of said component against said load cell.   
     
     
       18. Apparatus for testing brake actuator units for use in railway cars, comprising: a. a test stand;   b. mounting brackets located on said test stand to mount the brake actuator unit to the stand; and   c. a control arrangement for applying pressurized air to the brake actuator unit and monitoring for pressure drop indicative of air leakage within a cylinder of said actuator unit, said control arrangement including an air circuit having a source of pressurized air connected to the cylinder through a pressure regulator and a directional valve, said pressure regulator regulating the pressure to a desired level and said directional valve being movable between open, closed and exhaust positions.   
     
     
       19. Apparatus for testing brake actuator units for use in railway cars, comprising: a. a test stand;   b. mounting brackets located on said test stand to mount the brake actuator unit to the stand;   c. a pressure transducer for monitoring the pressure supplied to the cylinder; and   d. a display meter to which the pressure transducer is connected, and a programmable logic controller (PLC) adapted to be actuated by said display meter which in turn actuates an identifying arrangement when predetermined leakage is present.   
     
     
       20. Apparatus for testing brake actuator units for use in railway cars, comprising: a. a test stand;   b. mounting brackets located on said test stand to mount the brake actuator unit to the stand;   c. a control arrangement for applying pressurized air to the brake actuator unit and monitoring for pressure drop indicative of air leakage within a cylinder of said actuator unit;   d. an identifying arrangement, responsive to a signal from the control arrangement, for identifying whether a predetermined amount of leakage is present; and   e. a load cell mounted to the test stand in operative alignment with a cylinder actuated component of the brake actuator unit to measure application of force of said component under extension by said pressurized air.   
     
     
       21. Apparatus of claim 20, further comprising a gauge and an indicator connected to the test stand and the cylinder actuated component to measure slack travel of said component. 
     
     
       22. Apparatus for testing brake actuator units for use in railway cars, comprising: a. a test stand;   b. mounting brackets located on said test stand to mount the brake actuator unit to the stand; and   c. a control arrangement for applying pressurized air to the brake actuator unit and monitoring for pressure drop indicative of air leakage within a cylinder of said actuator unit, said control arrangement further comprising a programmable logic controller and a diagnostic panel display, connected to said programmable logic controller, said diagnostic display panel including indicia for indicating the type of pressure test being conducted and further indicia indicating whether or not leakage occurs following completion of said pressure test.   
     
     
       23. Apparatus of claim 22, further comprising a control panel display connected to the programmable logic controller and including indicia representative of whether a unit under test has passed or failed the leakage test at both high and low pressure levels.